Bosch AL0739X Alternator

Bosch AL0739X Alternator Overview

The Bosch AL0739X is a remanufactured 12-volt alternator built for BMW charging-system applications that require a 140-amp output. It features an internal fan, internal regulator, clockwise rotation, and a 6-groove pulley for direct-fit service on select BMW 3 Series, 5 Series, M3, and Z3 models.

Bosch Premium Alternators are remanufactured, tested, and built to deliver consistent electrical performance and dependable operation. The AL0739X is a practical OE-style replacement for BMW owners addressing charging concerns on vehicles equipped with Bosch alternator applications.

Key Features

• 12-volt remanufactured alternator with 140-amp amperage rating
• Internal fan and internal regulator for integrated charging control
• Clockwise rotation with 6-groove pulley and 50 mm outside pulley diameter
• Aluminum case and aluminum case color for OE-style construction
• Includes pulley and external regulator listed in the product data
• Plug type 381 with rear-view plug clock position at 8 o’clock
• One-wire capable: No

Detailed Product Description

Built under Bosch’s remanufactured alternator line, the AL0739X is engineered for BMW charging systems that call for a 140-amp alternator. The unit uses an internal fan, internal regulator, and clockwise rotation, along with a 6S pulley setup to match the specified belt drive configuration. For shoppers searching for a Bosch alternator for BMW 328i, BMW M3 alternator replacement, or a BMW Z3 charging system repair, this part number provides a direct-reference option for the listed applications.

This part cross-references Bosch OE numbers 12311738351 and 12311744563 for the same application.

Vehicle Fitment

• Fits 1999-2000 BMW Z3, N/A; to 140 amp alternator.
• Fits 1998-1999 BMW 323i, N/A; to 140 amp alternator.
• Fits 1998-1999 BMW 323is, N/A; to 140 amp alternator.
• Fits 1996-1999 BMW 328i, N/A; to 140 amp alternator.
• Fits 1996-1999 BMW 328is, N/A; to 140 amp alternator.
• Fits 1996-1999 BMW M3, N/A; to 140 amp alternator.
• Fits 1998 BMW Z3, N/A; to 140 amp alternator; with Bosch unit.
• Fits 1992-1995 BMW 320i, N/A; to 140 amp alternator; with Bosch unit.
• Fits 1992-1995 BMW 325i, N/A; to 140 amp alternator.
• Fits 1992-1995 BMW 325is, N/A; to 140 amp alternator.
• Fits 1992-1995 BMW 525i, N/A; to 140 amp alternator.
• Fits 1994 BMW M3, N/A; to 140 amp alternator; with Bosch unit.
• Fits 1993 BMW 525iT, N/A; to 140 amp alternator.
• Fits 1992 BMW 325i, N/A; from 10/1991; to 140 amp alternator.

Common Repair Uses

• Charging warning light or battery light on the dash
• Low system voltage during idle or driving
• Battery drain caused by alternator output loss
• Electrical accessories dimming under load
• Alternator noise or charging instability

Installation Notes and Quality

Verify the plug type, pulley configuration, rotation direction, and amperage rating against the original unit before installation. Confirm the vehicle’s alternator application by model year and Bosch-equipment notes, especially on BMW 320i, 325i, 328i, M3, 525i, and Z3 applications. Professional installation and charging-system testing after replacement are recommended to confirm proper output and belt alignment.

Bosch remanufactured alternators are built and tested for electrical performance and reliability, with OE-style specifications intended to match the listed BMW applications.